Lithium ion battery BMS

2021-09-15 17:09:31 0

As the core component of new energy vehicles, power battery packs account for a very high proportion of the cost of vehicle manufacturing, and its performance also affects the endurance and safety performance of the vehicle. The power battery also has an indispensable component, which is the BMS management system. So what is a BMS management system?

The battery management system, called BMS (Battery Management System) in English, is an important part of the power battery system of electric vehicles. It can detect, collect and preliminarily calculate the real-time battery status parameters, and at the same time control the on-off of the power supply loop based on the comparison between the detected value and the allowable value; in addition, it will also feed back the collected key data to the vehicle controller and receive the controller To coordinate with other systems on the car. Different battery cell types generally have different requirements for the management system.

The lithium-ion batteries used in electric vehicles have large capacity, a large number of series and parallel connections, complex systems, and high performance requirements such as safety, durability, and power, and are difficult to implement. Therefore, they have become a bottleneck affecting the popularization of electric vehicles. The safe working area of lithium-ion batteries is limited by the window of temperature and voltage. When the range of the window is exceeded, the battery performance will accelerate and decay, and even cause safety problems.

The main purpose of the battery management system is to ensure the design performance of the battery system, providing functions from three aspects: safety, durability, and power. In terms of safety, the BMS management system can protect battery cells or battery packs from damage and prevent safety accidents. In terms of durability, even if the battery works in a reliable and safe area, the service life of the battery is prolonged. In terms of power, the working state of the battery should be maintained to meet the requirements of the vehicle.

There are many fast cells in a set of lithium-ion battery packs. How is the BMS managed? The important work of the BMS system is divided into two major tasks: battery testing and ensuring the safety of lithium-ion batteries.

Among them, the realization of battery detection is relatively simple. The important thing is to collect the parameter information of the battery during use through the sensor, such as temperature, voltage and current of each battery cell, and voltage and current of the battery pack. These data will play a vital role in the subsequent battery pack management. It can be said that without these battery status data as support, the system management of power lithium-ion batteries will be impossible to talk about.

The important functions of the battery management system can be broken down into the following three aspects:

1. Safety, to protect battery cells or battery packs from damage and prevent safety accidents;

2. Durability, make the battery work in a reliable and safe area, and prolong the service life of the battery;

3. Power, to maintain the battery working in a state that meets the requirements of the vehicle.